Chicago is the largest city in the U.S. state of Illinois, and with more than 2.8 million people, the 3rd largest city in the United States. Located on the southwestern shores of Lake Michigan, Chicago is the third-most densely populated major city in the U.S., and anchor to the world's 26th largest metropolitan area with over 9.5 million people accross three states.

After a series of wars with the local Native Americans, Chicago was founded in 1833, near a portage between the Great Lakes and the Mississippi River watershed. The city became a major transportation and telecommunications hub in North America. Today, the city retains its status as a major hub, both for industry and infrastructure, with its O'Hare International Airport as the second busiest airport in the world. In modern times, the city has taken on an additional dimension as a center for business and finance, and is listed as one of the world's top ten Global Financial Cneters. Chicago is a stronghold of the Democratic Party, and has been home to influential politicians, including the current president of the United States, Barack Obama. The World Cities Study Group at Loughborough University rated Chicago as an alph world city.

In 2007, the city attracted 32.8 million domestic visitors and about 1.15 million foreign visitor. Making use of its abundant resources, Chicago has a heritage for hosting major international, national, regional, and local events that include commerce, culture, entertainment, politics, and sports. Globally recognized, Chicago has numerous nicknames, which reflect the impressions and opinions about historical and contemporary Chicago. The best known include: "Chi-town": "Chi-city"; the "Windy City" with reference to Chicago politicians and residents boating about their city; "Second City", due to the city generally being the second most prestigious in the nation in terms of culture, entertainment, and finance: and because for much of the twentieth century Chicago's population was teh second largest of any city in the United States, and the "City of Big Shoulders", regerring to its numberous skyscrapers (whose steel frame designs were largely pioneered in Chicago), described as being husky and brawling.Official state flower: dooryard violetOfficial state bird: Cardinal